The No. 2 U.S. drugmaker on Friday reported net income attributable to Merck of $1.74 billion, or 56 cents per share, for the first quarter. That compared with $1.04 billion, or 34 cents per share, a year earlier.

Excluding special items, the company earned 99 cents a share. Analysts, on average, had expected 98 cents, according to Thomson Reuters I/B/E/S.

Sales of Gardasil, a vaccine to prevent cervical cancer, jumped 33 percent to $284 million, helped by its introduction in Japan and increased vaccination of males aged 9 through 26. With vaccinations, boys are less likely to become infected with the human papillomavirus and sexually transmit it to others.